Directed Self Assembly (DSA) process is currently being developed for lithography processes. In conventional DSA processes, a photo resist is formed and patterned, followed by the dispensing of a Bulk Co-Polymer (BCP) coating. The BCP coating comprises Polystyrene (PS) and Polymethyl Methacrylate (PMMA). An anneal step is then performed to cause a phase separation in the BCP, so that the PS and PMMA are separated into parallel strips that are parallel to the edges of the photo resist. The PMMA strips are then etched, and the PS strips remain. The PS strips are used as an etching mask to etch an underlying layer.